When creating a Soapbox Mailer email, you'll likely want to send a test to just a few people, not all your recipients. Here's how to do this.
Preview your email via a test email send
If you want to see how your email looks within an email client or service (like Outlook, Gmail, etc), you'll want to send the email just to yourself or other testing recipients. To do this, either add only your testing email addresses as Campaign Members for the Campaign and set their statuses as "Targeted", or if you've already added all of your intended recipients for your campaign, change all their Campaign Member statuses to "Responded", and then your testing addresses' Campaign Member statuses to "Targeted". Then, click the Send button in the Campaign to have the email sent to your test recipients. This will send the email to only your test email addresses for review before sending out to your full list of recipients.